Unable to cancel ADSL service

The service cannot be called pathetic - it is simply non-existent! The idea of using an online system does simplify the methodology - but there needs to be a clearly published escalation process that the public can easily access.... In November 2017 I submitted the required forms to cancel our ADSL service. In January I re-submitted the forms as nothing had been done. I have sent the forms every month on receipt of the Telkom invoice which still shows a charge for services we are no longer using and have requested cancellation of. What other recourse do we have - we can stop all payments of the invoicing as this account should be in credit by about R4000-00 according to our calculations - if the cancellation was completed as first requested. Are there any other options? What other steps can we take? Who can we see? Perhaps it is time for the minister to get involved?